What is the primary function of a virtual switch?

The primary function of a virtual switch is indeed to build a table that identifies MAC addresses connected to its ports. In a virtualized environment, a virtual switch acts much like a physical switch but operates in software, enabling communication among virtual machines (VMs) on the same host or across different hosts.

When a VM sends traffic, the virtual switch learns the MAC address of the VM and associates it with the port on which it is connected. This process creates a MAC address table, which helps the virtual switch efficiently direct packets to the appropriate destination rather than flooding all ports with broadcast traffic. This behavior ensures that data is transmitted effectively within the virtualized network, minimizing unnecessary traffic and improving performance.

While routing traffic between different networks, filtering network traffic based on security rules, and connecting wireless devices are all important networking tasks, these functions do not define the primary purpose of a virtual switch. Routing involves different hardware and functionalities not intrinsic to a virtual switch, filtering typically utilizes firewalls or security appliances, and wireless connectivity is handled by wireless access points rather than by switches, virtual or otherwise.